Title: Systems Science Approaches for Assessing Cumulative Impacts of Air Pollution and Psychosocial Stressors on Neurocognitive Outcomes Among Children Abstract: The research objective of this TIEHR Career Award (K01) is to evaluate the effects of ambient air pollution exposures and psychosocial stressors on disparities in children?s neurocognitive functioning using epidemiological and systems science modeling approaches. The central hypothesis is that exposures to multiple environmental contaminant/pollutant and nonchemical stressors create disparities in and enhance adverse neurodevelopment among children. Emerging science is demonstrating enhanced toxic effects of cumulative exposures to chemical and social stressors on cognitive outcomes in children and adults, indicating that these disparate stressors affect common biological substrates. However, current environmental policies regulate single contaminant /pollutant exposures determined in the absence of any social/physical context, likely underestimating true health risks. The research is structured around three Specific Aims. Aim 1 involves assessing the association of cumulative early life exposures to PM2.5 and psychosocial stressors with children?s cognitive function using data from the ECLS Birth Cohort (n=5,800) and testing whether race/ethnicity and sex modify these associations. For Aim 2, a systems causal loop diagram will be developed to examine the pathways for cumulative effects of environmental neurotoxicants and social stressors on children?s neurodevelopmental disorder disparities using a participatory systems model building approach. Results from Aims 1 and 2 will inform simulation modeling in Aim 3. Aim 3 involves constructing a preliminary quantitative system dynamics simulation model for assessing cumulative air pollution and social stressor exposure impacts on population level trends in children?s cognitive outcomes. The K01 TIEHR Career Award Candidate is a tenure-track Assistant Professor with the Maryland Institute for Applied Environmental Health in the Department of Epidemiology and Biostatistics at the University of Maryland School of Public Health. Her long-term career goal is to develop scientific leadership in research addressing cumulative effects of social and environmental neurotoxicant exposures that can negatively affect children?s cognitive abilities, academic performance and consequent educational trajectories, adult health, wealth and social status. This K01 award will support her didactic and experiential training in 1) neurobiological mechanisms involved in children?s cognitive outcomes, 2) new skills in environmental epidemiology research using large datasets, and 3) application of systems modeling to health disparities. Her home institution has expertise in environmental epidemiology, biostatistics and health disparities research. This research will contribute significantly to the development of systems models to examine the potential heightened impact of cumulative exposures that adversely impact brain development, an area of strategic interest to the mission of NIEHS.